Published: Friday, November 16, 2012 at 10:21 a.m.

Last Modified: Friday, November 16, 2012 at 10:21 a.m.

Two people remain missing in the waters off Grand Isle after an explosion set an offshore oil platform on fire Friday morning.

At least four people were critically injured with severe burns, and U.S. Coast Guard crews continued searching for the two missing workers into the night.

There were 22 workers aboard the production platform. Eleven were flown to local hospitals and nine others with no injuries were rescued, said Coast Guard Petty Officer John Lally.

Coast Guard Capt. Ed. Cubanksi said the explosion was triggered by workers using a cutting torch on a 75-foot pipe.

The explosion and resulting fire about 25 miles southeast of Grand Isle sent a black plume of smoke high over the Gulf.

"We were heading into Grand Isle and heard the mayday, so we turned around," said Brett Rodrigue of Houma, who is a deckhand on a platform-servicing vessel in the Gulf. "The first thing we saw was that big ole plume of smoke."

The platform, owned by Houston-based Black Elk Energy, was "shut-in" for maintenance and was not producing oil at the time of the explosion, Lally said.

Cubanski said the pipe workers were cutting contained about 28 gallons of oil, and a light sheen about a half mile long was reported at the scene.

Taslin Alfonzo, spokeswoman for West Jefferson Medical Center, told The Associated Press four injured workers were brought to the hospital in critical condition with second- and third-degree burns over much of their bodies.

Two were sent by ambulance to the Baton Rouge Burn Center. Two others were to be sent later. She could not release identities or any other information.

A spokeswoman for Terrebonne General Medical Center in Houma said the hospital was treating two workers who were in good condition.

Several other workers were taken to Lady of the Sea General Hospital in Cut Off. No one was listed in critical condition, according to a spokeswoman, who wouldn't specify how many patients the hospital was treating.

Grand Isle Fire Chief Aubrey Chiasson said three were treated for minor injuries on the island.

The explosion came one day after BP plead guilty to several criminal charges tied to the 2010 Deepwater Horizon oil spill.

Unlike Deepwater Horizon, the fire was contained within hours and the platform appears to remain structurally sound, Cubanksi said.

The platform is also in much shallower water at 56 feet compared to Deepwater Horizon, which had a wellhead about a mile below the Gulf's surface.

Coast Guard officials said there was nothing to indicate oil was flowing from the well.

A federal official in Washington said a team of environmental enforcement inspectors was flying to the scene.

David Smith, a spokesman for the Interior Department's Bureau of Safety and Environmental Enforcement, said the team was dispatched from a Gulf Coast base by helicopter soon after the Coast Guard was notified of the emergency. Smith said the team would scan for any evidence of oil spillage and investigate the cause of the explosion.

"This is yet another reminder that our work on oil drilling safety is not complete," said U.S. Rep. Ed Markey, the top Democrat on the House Natural Resources Committee.

Black Elk Energy's website says the independent oil and gas company holds interests in properties in Texas and Louisiana waters, including 854 wells on 155 platforms.

"Our thoughts and prayers are with those who are impacted," the company said on its website.

The company said it was still collecting information and would issue a statement at a later date.

<p>Two people remain missing in the waters off Grand Isle after an explosion set an offshore oil platform on fire Friday morning. </p><p>At least four people were critically injured with severe burns, and U.S. Coast Guard crews continued searching for the two missing workers into the night. </p><p>There were 22 workers aboard the production platform. Eleven were flown to local hospitals and nine others with no injuries were rescued, said Coast Guard Petty Officer John Lally.</p><p>Coast Guard Capt. Ed. Cubanksi said the explosion was triggered by workers using a cutting torch on a 75-foot pipe.</p><p>The explosion and resulting fire about 25 miles southeast of Grand Isle sent a black plume of smoke high over the Gulf. </p><p>"We were heading into Grand Isle and heard the mayday, so we turned around," said Brett Rodrigue of Houma, who is a deckhand on a platform-servicing vessel in the Gulf. "The first thing we saw was that big ole plume of smoke." </p><p>The platform, owned by Houston-based Black Elk Energy, was "shut-in" for maintenance and was not producing oil at the time of the explosion, Lally said. </p><p>Cubanski said the pipe workers were cutting contained about 28 gallons of oil, and a light sheen about a half mile long was reported at the scene. </p><p>Taslin Alfonzo, spokeswoman for West Jefferson Medical Center, told The Associated Press four injured workers were brought to the hospital in critical condition with second- and third-degree burns over much of their bodies. </p><p>Two were sent by ambulance to the Baton Rouge Burn Center. Two others were to be sent later. She could not release identities or any other information. </p><p>A spokeswoman for Terrebonne General Medical Center in Houma said the hospital was treating two workers who were in good condition.</p><p>Several other workers were taken to Lady of the Sea General Hospital in Cut Off. No one was listed in critical condition, according to a spokeswoman, who wouldn't specify how many patients the hospital was treating. </p><p>Grand Isle Fire Chief Aubrey Chiasson said three were treated for minor injuries on the island.</p><p>The explosion came one day after BP plead guilty to several criminal charges tied to the 2010 Deepwater Horizon oil spill.</p><p>Unlike Deepwater Horizon, the fire was contained within hours and the platform appears to remain structurally sound, Cubanksi said.</p><p>The platform is also in much shallower water at 56 feet compared to Deepwater Horizon, which had a wellhead about a mile below the Gulf's surface. </p><p>Coast Guard officials said there was nothing to indicate oil was flowing from the well. </p><p>A federal official in Washington said a team of environmental enforcement inspectors was flying to the scene. </p><p>David Smith, a spokesman for the Interior Department's Bureau of Safety and Environmental Enforcement, said the team was dispatched from a Gulf Coast base by helicopter soon after the Coast Guard was notified of the emergency. Smith said the team would scan for any evidence of oil spillage and investigate the cause of the explosion. </p><p>"This is yet another reminder that our work on oil drilling safety is not complete," said U.S. Rep. Ed Markey, the top Democrat on the House Natural Resources Committee. </p><p>Black Elk Energy's website says the independent oil and gas company holds interests in properties in Texas and Louisiana waters, including 854 wells on 155 platforms.</p><p>"Our thoughts and prayers are with those who are impacted," the company said on its website.</p><p>The company said it was still collecting information and would issue a statement at a later date.</p><p>The Associated Press contributed to this report.</p>